Governing means for pneumatic systems



Jan. 30, 1923. 1,443,795.

1. G. MACLAREN. GOVERNINGIMEANS FOR PNEUMATIC SYSTEMS.

FILED OCT-211918- 5 SHEETS-SHEET I.

Jan. 80, 1923.

61,443,795. J. G. MACLAREN.

GOVERNING MEANS FOR PNEUMATIC SYSTEMS. FILED ocr.2, 1918.

3 SHEETSSHEET 3.

Amns o; MACLAREN, or MAMABDNECK, new Yess.

GOVERNING MEANS FOR PNEUMATIC SYSTEMS.

Application filed October 2, 1918. Serial No 256,509.

To all zr/ am 1'! may concern Be' it known that l, JAMESli. :llACLARl'IN, aucitizen of the l'nited States, and a resident of Blamaroncclt. county of ll'estchester, anclState (if New Yorlg have invented an Improvement in Governing Means for lneumatic Systems of hich the following description,' in connection with the accompanying drawings, is a specification. like characters onthe drawings representing like parts. 7

Thisinvention relates to pneumaticdispatch systems and inparticulai' to means for governinp an'electrically operated or electrically controlled mechanism in conjunction with the movement of the carriers in such a system.

My invention is adapted for the government of various mechanisms which it might be desired to 0 crate in conjunction with such a system. or purposes ofillustration I have shown an installation wherein the mechanism governed is an electric motor driving an exhnuster which provides suitside, and a return tube 9.

' able sub-atmospheric pressure in the transit tubes to move the carriers therethrough. My invention will best be understood by deference to the following description of the illustrative embodiment thereof shown in the. accompanying drawings wherein 2- Figure 1 is a, general and partly diagrammatic view of the installation and constitutes a wiring diagram;

Fig. 2 is a central vertical section through a casing forming part of the air'conduit and showing the main controlling mechanism; Figs. 3 end 4 are-sections on the lines 33 and M respectively of Fig; 1.

' Referring to Fig. 1 of the drawings, I have there shown my invention as applied to a pneumatic system operated b .sub-atmos pheric pressure or vacuum 3m have, shown '.a double tube vacuum line comprising a dispatch tube 7 leading from the main terminal station at the left hand side of' the figure to the-branch station at the upper righthand operating pressure is provided in these tubes by means of an exhauster ll driven bynin electric motor 13 which draws air through the tubes through the connecting conduit 15 which includes as a part thereof, a casing 1 hereinafter to be referred. to. In the present embodimentof my invention the driving ac tion of the electric motor 13 is governed in correlation with the movement of carriers in the tubes 7 and 9.

Any suitable means may be provided for starting the motor when a carrier is introduced into one of the tubes. l have here shown push buttons 1%) and til at the intake ends of the tubes adapted to be operated when a carrier is placed therein. The manner in which these push buttons start the motor into action will be more fully described hereinafter. in the form here illustrated the mechanism which more par-f ticularly involves the novel principles of my invention is adapted to dcenergizc the motor 13 when the arricr has left or is about toleuve the transit tube.

For thispurposc I make use of responsive mechanism governed by the speed of the an drawn through the system. understood thatii the carrier tubes are It will be empty and the motor is in motion, air will be drawn from the tubes at a definite speed. It will also be clear that, except under particular circumstances hereinafter to be more fully referred to the presence of a carrier will obstruct thetubes and retard the speed of the air. I make use of thistuct in controlling the driving: motor 13 or other desired mechanism correlatively to the passage.

of carriers. Q

Referring more particularly to Fig. 2, I

have there shown one suitable form of air speed responsive mechanism housed. in

duit of the system. As shown in that figure l may provide a motor in the form of a fan 23 mounted on .a 5 indie 25 revolving in suitable bearings 21 and 29 one of which is ina spider Within the casing and the other in the Wall thereof, as shown. As will be readily understood, the spindle 25 will be revolved by the fan at a speed de pendent upon the speed wiith which air passes through the casing 17. I

Mounted on the spindle 25 exteriorly of the casing is a collar 31, and adapted to slide on the end of the spindle is a sleeve 33 carrying a similar collar 35 connected to the first by flat springs 37 to wh ch are at tached weights 39, the whole forming a cen trifug'a-l overnor the spindle 25 rotates, the weights 39w1ll of Well known type. As'

tend to fly outwardly, bending the springs and drawing the movable collar 35 up towards the fixed collar 31. The parts may be so designed that this movement may utilized, when the fan reaches certain cr1tical speed, to operate a controlling element which in turn may be used to tie-energize the motor 13 or to operate any other desired mechanism.

l-lel'erring to Fig.2. l have there shown the speed responsive device operating an electric switch, which mechanism may be housed in a box or case 40 attached to the side of the casing 11'. in the figure I have shown a. switch lever -ll mounted on rock shaft :33 and 'car'ying the contact maker -l5 electrically connectedby the flexible conductor -17 to binding post l9 and adapted to be swung clockwise by the spring 51 to engage contact 53. Attached to the rock shaft i3 is a lever normally depressed by the collar 35 to toe position shown Fig. 2 and in that position holding the contact maker away from contact 53 against the force of spring 51. As the speed of air in the conduit rises, rotating the fan 23, the centrii'ugally moving weights 39 will lift the collar 35 upwardly and permit the spring 51 to swing switch lever 4-1 and bring contact maker 45 against contact 53. This action may be used to energize any d sired circuit such the one herein shown by way of illustration and which I shall now more fully describe.

Before proceeding to a detailed description of the electrical installation shown in the illustrative embodiment of my invention, l shall. to facilitate the understanding thereof, first. describe some of the specific mechanisms here illustrated. These mechanisms ap pear herein as mounted on a suitable panel board 57, shown at the lower right hand portion of Fig. l.

The circuit of the driving motor lflfi may be opened and closed by means of a suitable electrically operated switch (left hand side of panel board), the switch lever 59 herein forming the armature or a magnet 91.. The construction oi this switch will best be understood from Fig, 3. .Vi'hen the magnet- 61 is energized, attracting the armature, the spring-pressed plunger 63 will engage contact (35 and connect the same through the armature with binding post 6? through the copper strips (39. The switch lever or armature 59 is herein also provided with a downwardly extending arin Tl which car ries (see Fig. l) a bridge rod 73 which when the armature is attracted connects the spring contact leaves 75 and 77, in the present form of the invention the currentis supplied to the motor 13 while the switch 59 is closed and therefore thereis here provided a holding circuit therefor which thigh?) aptly be called a controlling circuit the continued action of the motor is dependent thereon. This holding circuit may lnclude, a circuit closer in the form of 'a pivoted bridge 7 9 (see the upper right hand corner of the board 57) which normally connects contacts 81 and 83. Herein this circuit closer is lifted to break the circuit and I may provide for this purpose a solenoid 85 (see Fig. l) the core of which is adapted at the upper limit of its travel to engage and lift the bridge 79. The solenoid is herein provided with suitable timing or retarding mechanism in the form of a dash pot 87 which causes the solenoid to lift the bridge 79 only at a definitely fixed time after its energization. I

I shall next describe the circuits by which the motor 13 is governed in connection with the dispatch of carriers through the tubes .7 and 9 by means of the installation here shown, disregarding the many variations that might be made therein within the scope of my invention and reserving for the claim the broader statement of the essential principles underlying the same. Referring to Fig. 1, we may assume that a carrier is introduced in tube 7 at the lower end thereof:

Suitable controlling means are provided tor starting the motor, herein exemplified by the msh button 19. hen the operator, introduces the carrier he will depress button 19 thereby completing the following energizing circuit :-Positive line 89 at the upper part of the board 57, wire'91, post 67, wire 93, coil of magnet 61, wires and 96, push button 19, wire 97, negative line 99. 'lhe magnet (31. being energized, attracts armature 59, rocking" i counterclockwise viewing Fig. -;-l and i: aging plunger 63 against contact 6:"). This completes the circuit tor motii is, "alloivsz -Positive line 89, wire 91, post or, armature 59, contact (if), wire 101. motor 13 and wire 103 to the negative line 99. As the push button 19 is only momentarily depressmb a suitable holding circuit for the magnet (51 is provided to con tinue the energization oi the motor. This holding circuit, which might aptly be called the controlling circuit since it contrils the energization of the motor, is as follows Positive line 89, wire 91, post 67, vvire 93, magnet coil 61, wire 95, wire 105 (which may include a suitable resistanceas shown), leaf contact 75, bridge 73, leaf contact 74', wire 107, contact 81, bridge 79, contact 93 and wire 109 to the negative line 99. This circuit will remain energized and continue the current in the motor circuit while bridge 79 remains in the position shown in the figures.

Herein the speed controlled mechanism shown in Fig. 2 is utilized to control the solenoid 85 which in turn lifts bridge 7 9 and breaks the holding circuit, /Ve'ma-y suppose that the carrier has passed through the.

tube which is no loneer; obstructed The shown at the left hand side of ig. 1.

speed of air in the tube then rises, the fan 23 revolves faster, and the centrifugal mechanism acts to release switch lever 41 to the spring, thereby connectim 49 and 53 This action completes an energizing circuit for the solenoid S as follows :lositive line 89,

circuit to the motor is broken and the motor stops. i

The utilization of a timed mechanism such as the solenoid and its cooperating dash pot 8T insures discharge of the carrier and also takes care of the special condition before referred to. It may happen that in the carrier tube there is asharply descending portion in which the carrier under gravity will descend so swiftly as not to obstruct the movementof the air in the tube. Thus, the fan 23cmay then speed up and the contact maker -15 close its circuit before the carrier is discharged. The action of the motor will not, however, be interrupted until a measured time after the circuit is closed at 49, 53. 'lheretore, alter the carrier has passed the sharply downwardly tending portion of the tube, the speed of the air in the tube will again decrease, the circuit will be opened again at +9, 53 and the solenoid 85 deenergized before its core. has acted to lift bridge 79. The core will then drop and the parts he in their initial position ready to operate as described when the carrier is discharged from the tube. i In many instances in this specification reference is made to the closing of a circuit, to the energization of a mechanism and the like. It has been done for clearness and definitcncss of description. Obviously, in yarious instances the same effect might be prodared-by the opening of a circuit or the (lee-nergization' of themechanism by changes within the skill of an electrician without dcparting from the spirit of my invention.

Having thus described the particular mechanism and the particular wiring thereof herein shown forthe. purpose of illustrating a specific embodiment of my invention. the principles exemplified thereby which I consider new and desire tosecure by Letters Patent I shall express in the following claims v LIn pneumatic dispatch apparatus, a

i transit tube means for producing a. flow of air-through the transit tube to propel a carrier thercthrough, a conduit between said means and said tube, means for initiating a carrier-propelling flow'of air and means in the conduit for automatically stopping the carrier-propelling flow of air when a carrier has completed its travel through the tube, said means including a device responsive to the rush of air following the discharge of a carrier from the tube.

e111 pneumatic dispatch apparatus, a central station, an outgoing transit tube leading from the central station andterminating at a distant station, an incoming transittube having a connection at the 'distant station with the outgoing'tube through which air may flow from one tube to the other, means at the central station having a conduit connection with one of said transit tubes toproduce a carrier-propelling flow of air through said transit tubes, means for initiating a carrier-propelling flow of air, and means for automatically stopping the carrier-propelling flow of air when a carrier has completed its travel througheither transit tube, said means including a movable vane mounted in said conduit connection and operable by the rush of air following the discharge of a carrier from the tube.

.3. A pneumatic dispatch tube apparatus comprising transit tubes through which car-- riers areJnoved by an air current, an electrical mechanism associated therewith, an electrically energized device ,for breaking the controlling, circuit of said mechanism, means for definitely retarding the operation of said device after the energizing thereof anr emeans for energizing the, same comprising a device responsive to the velocity changes of the air ina tube due' to the transit of a carrier and a circuit closer moved by said responsive de 'ice and providing for the energization aforesaid.

4. The method of operating mechanisms which are associated with pneumatic dispatch tube systems in correlation with thetransit of a carrier through a tube characterized by initiating the operation ot a retarded con.--

trolling device conse quentially on achange in velocity of the air in the system due to the 115' tube, means for initiating a carrier-propel ling flow of air, and means for stopping the 'carrier-propelling flow of air when ararrier has completed its travel through the tube, said stopping means including a control deviceexternal to the conduit connection and a vane'mounted in the conduit connection and operable by the rush of air following the discharge of a carrier from the =;ube..

6,111. pneumatic dispatch npgiai'imis, s ccn'i-i'al station, a disiant station, a timsit tube crmn ccting said stations, means at the central station having a conduit connectian with said transit tube for prnducing: a cam Pier-propelling flow of air through said tube, means far initiaiing u csi'ricr-prepeliing flow sf air, and iileans, for stopping the marrier pmpeiiing flow of air when a carrier has cnmpieted its travel through iii-e tube, saidisiogping means including a can trol device external to the conduit QUEBEC-- tion and a mambcr mounted to extend 'thi'nugh a Willi (if the cpnduit connection,

that portion of the member sxtendin into tbs Cfifldlllii (wunection being nrovidc with s vane npembie by ths i'ush of air foiiowin ihc discharge of a carrier from the tube anii ihntfiiortinn cf flu. member amending out side the condfnit connection serving to operate the contijnl device,

I. Inn pnctumatic dispatch apparatus, a

central statibn, a distant station, a transit tube connectinghsaid stations, means at the @smi'ni statio'n swing a conduifi connection wiiih said transiis tube for producing a carnisr propellirig flow of air throughsaid tube, 

